Sriwibowowati, Sunan Mukti (2018) Analisa Banjir Akibat Keruntuhan Bendungan Bajulmati dengan Menggunakan Program HEC-RAS. Sarjana thesis, Universitas Brawijaya.
Abstract
Infrastruktur memegang peranan penting dalam mendukung pertumbuhan ekonomi nasional dan daya saing global. Salah satu infrastruktur untuk mewujudkan ketahanan air dan ketahanan pangan adalah dengan dibangunnya 65 bendungan pada periode 2015-2019, Kementerian Pekerjaan Umum dan perumahan Rakyat, melalui direktorat Jendral Sumber Daya Air sehingga ketersedian air di Indonesia akan meningkat menjadi 19,1 miliar meter kubik. Pembangunan suatu bendungan disamping mempunyai manfaat yang sangat besar bagi manusia juga menyimpan potensi bahaya yang sangat besar, dimana bila bendungan tersebut runtuh dapat mengakibatkan bencana yang sangat besar di daerah hilir. Menurut penelitian yang dilakukan oleh Costa, penyebab keruntuhan bendungan urugan seringkali disebabkan oleh overtopping dan juga piping. Keruntuhan bendungan akibat overtopping terjadi karena melimpahnya air pada waduk melalui tubuh bendungan, sedangkan keruntuhan bendungan akibat piping tidak bisa dipastikan awal mula lokasinya dikarenakan gerusan yang diakibatkan oleh rembesan terjadi di dalam tubuh bendungan. Maka perlu dilakukan studi analisa keruntuhan bendungan yang nantinya dapat diketahui wilayah-wilayah yang terkena dampak bencana Tujuan penelitian ini adalah melakukan analisa dari alternatif keruntuhan bendungan dengan menggunakan program HEC-RAS versi 5.0.3 yang dikembangkan oleh Hydrolic Engineering Center dalam berbagai skenario keruntuhan bendungan. Dalam penelitian ini, dilakukan simulasi keruntuhan bendungan akibat overtopping dengan memasukkan parameter rekahan tertentu guna mendapatkan sebaran genangan banjir yang terjadi. Selain akibat overtopping, banjir pada keruntuhan bendungan akibat piping juga disimulasikan. Waduk Bajulmati merupakan waduk yang dibangun untuk memenuhi kebutuhan irigasi sebanyak 1800 ha di daerah irigasi Kabupaten Situbondo dan Banyuwangi. Batas hilir dari Bendungan Bajulmati berada di Selat Bali. Pada hilir Bendungan Bajulmati perkembangan masyarakat di daerah hilir menjadi daerah pemukiman, pertanian, industri, perdagangan dan banyaknya fasilitas umum, hal ini menyebabkan makin bertambahnya tingkat bahaya akibat keruntuhan bendungan.. Keruntuhan Bendungan Bajulmati dapat disebabkan karena overtopping dan piping. Dari simulasi yang dilakukan, keruntuhan overtopping merupakan peyebab keruntuhan Bendungan Bajulmati yang menimbulkan dampak paling besar dengan banjir desain PMF dengan puncak debit QInflow sebesar 2490.878 m³/det dan menghasilkan luas genangan sebesar 1646.0146 ha dengan tinggi genangan maksimum sebesar 21.31 m. Akibat dari keruntuhan Bendungan Bajulmati ini terdapat 5 desa di 2 kecamatan di bagian hilir Bendungan Bajulmati yang terkena genangan. terdapat 7896 KK penduduk terkena risiko akibat dari keruntuhan Bendungan Bajulmati. Dengan jumlah penduduk terkena risiko tersebut dan jarak Bendungan Bajulmati sampai hilir yang sejauh 9 km, maka Bendungan Bajulmati termasuk dalam klasifikasi bendungan dengan bahaya tingkat 4 yaitu bahaya sangat tinggi. total kerugian yang harus ditanggung akibat banjir karena keruntuhan bendungan Bajulmati sebesar Rp 476,691,534,795.
English Abstract
Infrastructure plays an important role in supporting national economic growth and global competitiveness. One of the infrastructure to realize water security and food security is the construction of 65 dams in the 2015-2019 period, Kementerian Pekerjaan Umum dan perumahan Rakyat, through the Directorate General of Water Resources so that water supply in Indonesia will increase to 19.1 billion cubic meters. The construction of a dam in addition to having enormous benefits for humans also holds a huge potential danger, where if the dam collapses it can cause a very large disaster in the downstream area. According to research conducted by Costa, the cause of the collapse of the dam is often caused by overtopping and piping. The collapse of the dam due to overtopping occurs because of the abundance of water in the reservoir through the body of the dam, while the collapse of the dam due to piping cannot be ascertained the beginning of its location due to scour caused by seepage occurs in the body of the dam. Then it is necessary to do a dam collapse analysis study which will be known to the affected areas The purpose of this study was to analyze the dam collapse alternative using the HEC-RAS version 5.0.3 program developed by the Hydrolic Engineering Center in various dam collapse scenarios. In this study, a simulation of dam collapse due to overtopping was carried out by entering certain fracture parameters in order to obtain the distribution of flood inundation. In addition to overtopping, flooding in the dam collapse due to piping is also simulated. Bajulmati Reservoir is a reservoir built to meet the irrigation needs of 1800 ha in the irrigation area of Situbondo and Banyuwangi Districts. The downstream boundary of the Bajulmati Dam is in the Bali Strait. At the lower reaches of the Bajulmati Dam the development of communities in the downstream area becomes residential, agricultural, industrial, trade and many public facilities, this causes an increase in the level of danger due to the collapse of the dam. The collapse of the Bajulmati Dam can be caused by overtopping and piping. From the simulations carried out, overtopping collapse was the cause of the collapse of the Bajulmati Dam which had the greatest impact with the flood of PMF design with a peak flow of QInflow of 2490,878 m³ / sec and produced a pool area of 1646.0146 ha with a maximum inundation of 21.31 m. As a result of the collapse of the Bajulmati Dam there were 5 villages in 2 sub-districts in the lower reaches of the Bajulmati Dam which were inundated. there were 7896 KK residents of the affected by the risk of the collapse of the Bajulmati Dam. With the population affected by this risk and the distance of the Bajulmati Dam to the downstream which is as far as 9 km, the Bajulmati Dam is included in the classification of dams with level 4 hazards, namely very high hazards. the total loss to be borne due to flooding due to the collapse of the Bajulmati dam was Rp. 476,691,534,795.
| Item Type: | Thesis (Sarjana) |
|---|---|
| Identification Number: | SKR/FT/2018/1215/051900726 |
| Uncontrolled Keywords: | Keruntuhan Bendungan, Bendungan Bajulmati, Overtopping, Piping, HEC- RAS Collapse of Dam, Bajulmati Dam, Overtopping, Piping, HEC-RAS |
| Subjects: | 600 Technology (Applied sciences) > 627 Hydraulic engineering > 627.8 Dams and reservoirs > 627.802 85 Dams and reservoirs (Computer applications) |
| Divisions: | Fakultas Teknik > Teknik Pengairan |
| Depositing User: | Budi Wahyono Wahyono |
| Date Deposited: | 13 Mar 2019 07:25 |
| Last Modified: | 29 Mar 2022 01:39 |
| URI: | http://repository.ub.ac.id/id/eprint/163073 |
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